mould growth in Richmond Hill attic

mould growth in Richmond Hill atticMould is a natural fungus that takes root in any humid or damp environment.  Here in Toronto, mould growth in the attic is common due to the change in seasons and temperature throughout the year.  If a roof leaks however slightly, the attic is rainwater’s first port of call. Moreover heat generated in a home rises upwards to combine with damp. In reality, the question really should be “why aren’t all attics mouldy”. Let’s take a look at the factors in the equation, and discover the reasons why.

Roof Seepage

Rainwater often seeps through roofing joints and hips especially when driven by accompanying rain. After the storm passes, sunlight bakes the roof and creates a haven for mould below. There really are only two solutions to avoiding this. Waterproof the roof and introduce cross ventilation.

Access Points between Home and Attic

Access panels and staircases provide essential access to roof-space for maintenance and inspection purpose. These also admit heat, and allow mould spores to enter. Access panels are easily insulated. However stairs usually require a pull-down box to address the problem properly.

Forced Ventilation from Below

Those innocent-looking bathroom, laundry and kitchen ventilation fans are actually your worst enemy, although you may look on them as your friends.  That’s because they not only incubate mould in cracks and crannies, they also literally blast the fungus into the attic in a cocoon of warm moist air.

Your first step is to track them down where they often lurk hidden under loft insulation (run them while you’re up there to locate them). You only have two options – either disable them, or duct them through to fresh air. Doing nothing is not a valid choice.

Gaps in Ceiling Insulation

Insulation gaps are another favourite friend of mould, because, just like water-proofing and security, insulation is only as good as its weakest point. Investigate all the tricky places where an installer might have been tempted to take short cuts. Skylights and dormer windows are a good start, as are pipes and cables that penetrate through walls and ceilings.

Furnaces and Water Heaters

Homes without basements often have heating systems installed in attics in separate rooms. Failure to insulate these properly can undo all the good intentions mentioned above. Pay special attention to seals around pipes and ducting where these pass through to living space, as these could admit mould spores in either direction.

Essential Maintenance

Nothing lasts forever (at least unless you keep a hand to it) and that includes all the mould defenses mentioned. Lint from ceiling fans and bird and ant nests are just a few of the things that can break down your mould barriers. If you suspect mould growth in your attic, the best thing to do is to call a qualified mould inspector to come in and conduct the proper testing.


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Waterproofing & Foundation Specialists at Nusite Contractors Ltd
As a family-owned waterproofing and foundation repair business with over 30 years of experience in Toronto, we are proud of our work and stand by it with a full warranty. We’re a service company, working for you. We make sure our customers understand the entire building and repair process, and ensure that our work is done properly and made to last.

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